Some great advice and thoughts on the creation process of transmedia storytelling from Andrea Phillips:
"The core goal should always be to create a compelling story.
Tangibility is a profoundly powerful thing. It’s why we bring back souvenirs from trips, and why we cherish old concert t-shirts, why we buy replicas of rings and swords from movies we love. It’s almost like locking all of the feelings and memories about a certain time and place into that object for safekeeping.
As an artist, of course I want to use that tool for the benefit of my story! And as a businesswoman, if people are willing to pay for that depth of experience, then I should definitely make it available.
You can make entirely nonlinear experiences, but they’re the exception, not the rule. That said, it is common for a minor component of a project to become a vector for introducing people to the greater work...
For an experience that plays out in real time, finding a way to catch up new audience members is an enormous challenge, but an important one if you want to keep your audience growing.
When you’re writing a complex work of fiction, it’s often the case that you’ll have a lot of information about backstory that you aren’t going to pass on to your audience. It might seem like a waste to generate that knowledge and then not use it as content. But sometimes it’s crucial to get your story straight about events and motivations you never want to spell out — you’re creating a negative space, and that space has to remain consistent. In order to preserve consistency, though, you have to be completely clear about what occupies that space.
The best (but still imperfect) advice I’d have is to understand what parts of your story are absolutely immutable, and which you can change. If you can cut something out of the story and still have a comprehensible story, then that element has to go through a harder vetting process. What is it adding? If you can’t put your finger on a rock-solid reason to keep it in, maybe that’s your signal that you shouldn’t include it at all."